DE102006050551A1 - Device for determining a phase position of two magnetic fields and method for checking stator windings - Google Patents

Abstract

The The invention relates to a device for determining a phase position of two magnetic fields (H1, H2), with a control and computing unit (108), two arranged at a predetermined distance (d), with the control and computing unit (108) connected magnetic field sensors (101, 102) and display means (103-107) connected to the control and computation unit (108), wherein the control and computation unit (108) is adapted to the phase position each of two another of the magnetic field sensors (101, 102) essential acting magnetic fields (H1, H2) from measured values (211, 212, 213, 214) of the magnetic field sensors (101, 102) and the display means (103-107) to control the indicate certain phase position. The invention further relates a method for checking Stator windings, in which in particular a device according to the invention can be used.

Description

The The present invention relates to a device for determining a Phase angle of two magnetic fields and a method for checking Stator windings of an electric motor or generator.

State of the art

It is necessary in the manufacture of an electric motor or a Generator to check the stator windings and their connections. Especially make sure that the direction of rotation of the rotor is relative to Stator is correct when the motor or generator is assembled. To do this the connections of individual stator windings are properly combined and, in the case of a three-phase motor, the correct phases of the three-phase current be assigned. Especially with new generations of electric motors Stator windings are often only after insertion into the stator connected, creating a number of possibilities for faulty Connections or cabling arise.

The possibility the incorrect assignment of the connections to the three-phase phases has already been mentioned. Other options are a missing connection of one or more windings with the rest, a misaligned insertion of a winding or swapping of two windings.

One Another problem when checking stator windings a motor or generator is that usually many different types, for example rotary or linear motors, synchronous or asynchronous motors, etc., as well as various sizes of Motors or generators are produced.

It is known, the direction of rotation, which is mediated by the stator, with to determine a kind of compass. For this purpose, for example a three-phase current to it provided connections a round stator to create a rotating inside the stator To generate magnetic field. The compass is inserted into the magnetic field, whereupon the needle starts to rotate. The direction of rotation can be selected by the user to be watched. It is not possible with this method, not or to detect incorrectly connected single windings. It can too Occur that the rotation of the magnetic field in a part of the stator not recognized in any other direction than in other parts. Also This procedure can not be for Linear stators are used.

at a method for checking a synchronous Linear motor is the magnetic field direction by means of three arranged on selected stator teeth Magnetic field sensors determined. This method is relatively expensive, because special equipment to accurately arrange the magnetic field sensors is necessary. Farther will be an extraordinary Power supply needed, to create a special magnetic field in the stator. These problems are continued by the presence of different stator types exacerbated.

It is therefore an object of the present invention, a method and to provide a device for magnetic field determination and an easy to perform, but still accurate verification of Stator windings of various types are suitable.

These Task is solved by a device for determining a phase angle of two magnetic fields with the features of claim 1 and a method for checking a stator winding with the features of claim 5. Advantageous embodiments are the subject of the dependent claims as well as the following description.

Advantages of the invention

A device according to the invention for determining a phase position of two magnetic fields is suitable for carrying out a method according to the invention and has corresponding means. A device according to the invention has, in particular, a control and computing unit, two spaced-apart magnetic field sensors connected to the control and arithmetic unit, whose spacing is in particular more than 10 mm and less than 30 mm, in particular 25 mm, as well as display means connected to the control and computing unit on. The control and computing unit is set up to determine the phase position of two magnetic fields from measured values of two magnetic field sensors, wherein each of the two magnetic field sensors is essentially acted upon by another of the two magnetic fields. The display means are controlled by the control and processing unit such that they indicate the specific phase position. It makes sense, especially in three-phase current, the value ranges from] - (π - a); -A [,] a; (π - a) [and [- a; a] and summarized for the display, where a should be chosen in the range around 0, in particular sufficiently smaller than π / 3. These areas can then be assigned the phase positions "minus", "plus" and "error" or "in-phase". The magnetic field sensors can be designed, in particular, as digital or analog Hall or magnetoresistance (MR) sensors or as Förster probes (fluxgate). It makes sense, for the control and processing unit, an integrated circuit or to use a microprocessor.

The Invention is based on at least two magnetic fields, as for example be generated by windings of a stator. At a first and a second magnetic field generated by two adjacent windings each of the magnetic fields is applied to a different one Magnetic field sensor essential, d. H. z. B. applied to the first magnetic field the first sensor more than the second sensor and the second magnetic field acts on the second sensor more than the first sensor.

With the solution according to the invention becomes a Device provided a simple and accurate determination the phase position between adjacent stator windings allows. The device can be made small and handy and proves in practice because of the simple structure as special robust and reliable. The device according to the invention is particularly well suited to the process of the invention to be used.

It is advantageous if the control and processing unit set up for it is to control the display means such that it is an admission show each of the magnetic field sensors with a magnetic field. In order to can be checked easily whether both magnetic field sensors are acted upon by a magnetic field, which, in particular, the integrity of a respective, the Check magnetic field generating stator winding.

Conveniently, the display means have at least one light emitting diode, a graphical Display and / or a numeric display. In addition, can the device has an interface z. B. for connecting to a Computer have. A preferred embodiment has three or five LEDs on. An inventive device with light-emitting diodes can be made very easily and is particularly suitable for displaying the magnetic field direction. Especially each one LED can be assigned to a magnetic field sensor be, as explained, to indicate the application of the magnetic field sensor with a magnetic field. In each case a light-emitting diode can for the display of the said phase position ranges can be provided.

The inventive device advantageously has a power supply device, in particular a battery, on. By providing a battery, the device can especially small and handy and easy to transport become. Alternatively or in addition The device can also be used for a supply from an external power supply device, for example, a power supply, be educated.

at the method according to the invention to check Stator windings of an electric motor or generator to which a electrical rotary or alternating current is applied, first becomes a first Phasing of the rotary or alternating current in a first pair adjacent stator windings generated magnetic fields determined. Subsequently, will the first certain phase position with a due to the applied Rotational or alternating current expected phase angle and / or with a second phase position of the rotary or alternating current in a second Pair of adjacent stator windings generated magnetic fields compared. Thereafter, the accuracy of the stator windings on the basis of Comparison determined. This experience is particularly easy to perform and for different Types of motors and generators suitable.

Conveniently, be in the inventive method the steps of determining a first phase position and comparing the first specific phase position with the expected phase angle and / or with the second specific phase () for further, in particular all, Pairs of adjacent stator windings () repeated.

In order to it is possible in a particularly simple and fast way, all Completely check stator windings.

It is preferred when the particular phase position is output numerically becomes. It can then be displayed in particular on a numeric display, via a existing interface etc.

It is particularly useful if a device according to the invention in the method according to the invention is used to determine the phase position. The device according to the invention are particularly suitable for use with the method according to the invention as well as generally for Procedure for checking Stator windings of an electric motor or generator, as they are special small and handy builds and is inexpensive to manufacture.

Further Advantages and embodiments of the invention will become apparent from the Description and attached drawing.

It it is understood that the above and the following yet to be explained features not only in the specified combination, but also in other combinations or alone, without to leave the scope of the present invention.

The Invention is based on an embodiment schematically shown in the drawing and is below under Referring to the drawings described in detail.

figure description

1 shows schematically the arrangement of an embodiment of the device according to the invention on a stator of a linear motor;

2 shows a diagram showing the sensor signals of two of the device according to 1 detected magnetic fields shows; and

3 shows a flowchart of an embodiment of the method according to the invention.

In 1 is a preferred embodiment of the device according to the invention in total with 100 designated. The device 100 has two as digital Hall sensors 101 . 102 executed magnetic field sensors and two associated, as LEDs 103 . 104 trained display means on. Furthermore, the device 100 as LEDs 105 . 106 . 107 trained display means, one as a microprocessor 108 executed control and processing unit and one as a battery 109 executed power supply device. The Hall sensors 101 . 102 , the LEDs 103 to 107 , the microprocessor 108 and the battery 109 are among themselves, if necessary on other components such. As resistors, capacitors, transistors, etc., as is known to a person skilled in the art.

The Hall sensors have a distance d from each other, which is 25 mm in the present example. The distance d is chosen so that the device 100 suitable for use with common stators. For example, the stator teeth of a type of modern motors have a tooth spacing D of about 25 mm. The device can be used in a particularly advantageous manner also for stators with a smaller tooth spacing by the device is aligned obliquely to the teeth. The distance d then corresponds to a diagonal of a rectangle whose one side is defined by the tooth spacing D.

The LED 103 is the sensor 101 , the LED 104 the sensor 102 assigned. The LEDs 103 and 104 be from the microprocessor 108 controlled so that they signal by lighting up or flashing, if the respective sensor 101 respectively. 102 is acted upon by a magnetic field. These LEDs assist the user in getting the device 100 to be arranged correctly over stator windings or stator teeth. Furthermore, the LEDs show 103 and 104 the magnetic activity of the respective stator windings.

In 1 is also a section of a stator 150 shown. The stator 150 has equally spaced teeth 151 to 154 on. The distance of the teeth 151 to 154 each other is D. In the example shown, the distance D corresponds to the teeth 151 to 154 from each other the distance d of the sensors 101 and 102 namely 25 mm.

Each of the teeth 151 to 154 has a winding 151 ' to 154 ' on. As is usual with three-phase motors, the single windings are 151 ' to 154 ' connected to each other such that every third winding is in communication with each other. In the example shown, the winding 151 ' with the winding 154 ' connected in series, etc. It is understood that a parallel connection is possible as well. When assembling the motor or generator, attention must be paid in particular to the correct wiring or connection of the individual windings with one another and the correct assignment to the phases U, V, W. A current through the winding 151 ' generates a magnetic field H1 etc.

To check the stator of this is connected with its terminals to the terminals U, V, W of a three-phase power source (not shown). As a result, a rotating magnetic field is formed by means of the device 100 can be checked.

The device 100 This is done successively via a pair of adjacent teeth 151 . 152 ; 152 . 153 ; 153 . 154 etc. arranged. The LEDs 105 . 106 are intended to indicate the phase of the two magnetic fields, the Hall sensors 101 . 102 apply. The phase position can be assigned to the direction of rotation of the rotor in an electric motor. The LEDs 105 . 106 be from the microprocessor 108 controlled in such a way that the LED 105 Illuminates (or flashes) when the magnetic field in the device plane (corresponding to the drawing plane) rotates to the left, whereas the LED 106 Illuminates (or flashes) when the magnetic field in the device plane (corresponding to the drawing plane) rotates to the right or wanders.

The movement or rotation direction can be derived from the phase angle of the magnetic fields. Hasten the sensor 102 Applying magnetic field H2 to the sensor 101 pre-loading magnetic field H1, this corresponds to a movement to the left, rushes the sensor 102 Applying magnetic field H2 to the sensor 101 impinging magnetic field H1 according to how it is in 2 is shown, this corresponds to a movement to the right.

The LED 107 is intended to indicate malfunctions. For example, is one under one of the sensors 101 . 102 lying winding not energized or the detected phase shift is insufficient, this is the LED 107 displayed. In this connection, reference is made to the constant a already described above, which describes a sufficient phase separation.

In a preferred embodiment of the method according to the invention for checking stator windings of an electric motor or generator, the user orders the device 100 successively over all pairs of stator windings 151 ' . 152 '; 152 ' . 153 '; 153 ' . 154 ' etc. or teeth 151 . 152 ; 152 . 153 ; 153 . 154 etc. and compares the displayed direction (phase angle) with the expected or previously displayed one. In the second case, make sure that each pair has the same direction either through the LED 105 or through the LED 106 is signaled.

Based 2 explains how the phase angle of two magnetic fields and thus the direction of rotation can be determined. In 2 is a diagram 200 imaged in the output signals of the magnetic field sensors 101 . 102 are applied against the time. The output signals are as voltages U on a y-axis 201 against time t on an x-axis 202 applied. In the diagram 200 are the temporal developments 211 . 212 the output voltages of the sensors 101 respectively. 102 applied. The voltage curve shown is composed of individual measured values (not shown) which each have a time interval in the range of a few ns. The sensors are designed as bipolar digital Hall sensors. Bipolar digital Hall sensors usually give a voltage in the presence of a magnetic field of a certain direction (eg, south to north), whereas in the presence of a magnetic field of the other direction (eg, north to south) they do not output voltage.

The measuring curve (voltage curve) 211 essentially corresponds to the time course of the sign of the magnetic field H1, which is the sensor 101 applied. The measurement curve also corresponds 112 essentially the time course of the sign of the magnetic field H2, the sensor 102 applied. The microprocessor 108 can determine the phase relationship of the two magnetic fields from the present course. It can derive the phase relationship in particular from the relationship to the rise or fall times of a selected sensor.

In the example shown becomes the sensor 101 selected and its output 211 at a (arbitrary) rise time (positive edge) compared to the output value of the other sensor. In the present case, a rise time 213 the trace 211 with an associated measured value 214 the curve 212 compared.

Is, as in the example shown, the output value of the sensor 102 at the time of rise 213 of the sensor 101 Zero, that rushes the sensor 201 or the trace 211 causing magnetic field H1 to the sensor 202 act on or the trace 212 causing magnetic field H2. This behavior is a direction of movement or rotation in the direction of the magnetic field sensor 102 assigned. The microprocessor 108 controls the LED in the sequence 106 at.

Is the output value of the sensor 102 at the time of rise 213 of the sensor 101 Positive (not shown), so the trace is hurrying 211 causing magnetic field H1 that the trace 212 causing magnetic field H2 after. This behavior is a direction of movement or rotation in the direction of the magnetic field sensor 101 assigned. The microprocessor 108 controls the LED in the sequence 105 at.

It It goes without saying that the falling edge is also considered can. Likewise it is for a professional possible, the phase position z. B. derive from the output data analog sensors.

In 3 Now, a preferred embodiment of the inventive method for checking stator windings of an electric motor or generator, to which an electrical rotary or alternating current is applied, explained with reference to a flowchart.

The process begins in one process step 301 , In a subsequent process step 302 is a device according to the invention, in particular the device 100 according to 1 , disposed above a first pair of adjacent stator windings such that each of the two magnetic field sensors can detect the magnetic field of a stator winding. The placement process is done by the LEDs 103 and 104 supports that light up or flash once a magnetic field from the associated magnetic field sensor 101 respectively. 102 is detected. Once the device is arranged as intended, the phase position of the microprocessor 108 determined and via the corresponding LEDs 105 to 107 displayed.

In a subsequent process step 303 the user repeats the activities in accordance with the method step 302 at a next adjacent pair of stator windings. At the end of the process step 303 the phase angle of this considered pair of stator windings can be read off.

In the subsequent process step 304 who now the two previously determined phase positions compared. If the two phases are the same, either becomes a process step 303 returned, looking at a next pair of stator windings, or the process in one step 305 terminated when all pairs of stator windings are already checked.

If the phase angles of two neighboring pairs of stator windings differ, this means a faulty stator winding, whereupon a step 306 branches and the process is terminated. The stator winding must then be repaired, for example, replaced or reconnected.

It is understood that in the illustrated figures only particularly preferred embodiments the invention are shown. Besides, every other embodiment, in particular by a different arrangement or number of sensors or other components conceivable without the scope of this invention to leave.

100

contraption

101 102

digital Hall sensor

103-107

LED

108

microprocessor

109

battery

150

stator

151-154

stator tooth

151'-154 '

stator

200

diagram

201

y-axis U

202

X axis t

211 212

sensor data

213

Ascending flank

214

Measured value at the time 213

301-306

step

H1-H4

magnetic field

U, V, W

Rotary current phases

Claims (9)

Device for determining a phase position of two magnetic fields (H1, H2), characterized by a control and computing unit ( 108 ), two at a predetermined distance (d) arranged, with the control and computing unit ( 108 ) connected magnetic field sensors ( 101 . 102 ), and with the control and computing unit ( 108 ) associated display means ( 103 - 107 ), wherein the control and computing unit ( 108 ) is adapted to the phase position of two each a different one of the magnetic field sensors ( 101 . 102 ) of magnetic fields (H1, H2) which are of considerable importance from measured values ( 211 . 212 . 213 . 214 ) of the magnetic field sensors ( 101 . 102 ) and the display means ( 103 - 107 ) in such a way that they indicate the specific phase position. Apparatus according to claim 1, characterized in that the control and computing unit ( 108 ) is arranged for, the display means ( 103 - 107 ) in such a way that it can be subjected to any magnetic field sensor ( 101 . 102 ) with a magnetic field (H1, H2). Apparatus according to claim 1 or 2, characterized in that the display means at least one light emitting diode ( 103 - 107 ), a graphic display and / or a numeric display. Device according to one of claims 1 to 3, characterized by a power supply device, in particular a battery ( 109 ). Method for checking stator windings ( 151 ' - 154 ' ) of an electric motor or generator to which an electrical rotary or alternating current is applied, characterized by the following steps: a) determining a first phase position of the rotational or alternating current in a first pair ( 151 ' . 152 '; 152 ' . 153 '; 153 ' . 154 ' ) of adjacent stator windings ( 151 ' - 154 ' ) generated magnetic fields (H1, H2); then b) comparing the first determined phase position with a phase position expected on the basis of the applied rotary or alternating current and / or with a second phase position of the rotary or alternating current in a second pair ( 151 ' . 152 '; 152 ' . 153 '; 153 ' . 154 ' ) of adjacent stator windings ( 151 ' - 154 ' ) generated magnetic fields (H2, H3); and c) determining the accuracy of the stator windings ( 151 ' - 154 ' ) based on the comparison. Method according to claim 5, wherein the steps of determining a first phase position and comparing the first specific phase position with the expected phase position and / or with the second specific phase position for further, in particular all, pairs ( 151 ' . 152 '; 152 ' . 153 '; 153 ' . 154 ' ) of adjacent stator windings ( 151 ' - 154 ' ) is repeated. Method according to claim 5 or 6, characterized that the specific phase position is output numerically. Method according to one of claims 5 to 7, characterized in that a device ( 100 ) according to one of claims 1 to 4 is used to determine the phase position. Using a device ( 100 ) according to one of claims 1 to 4 for checking Sta Torwicklungen ( 151 ' - 154 ' ) of an electric motor or generator.